Efficient synthesis of 3-chloromethyl-2(5H)-furanones and 3-chloromethyl-5,6-dihydropyran-2-ones via the PdCl2-catalyzed chlorocyclocarbonylation of 2,3- or 3,4-allenols.
A mild and efficient methodology involving PdCl2-catalyzed chlorocyclocarbonylation of 2,3- or 3,4-allenols with CuCl2 for the synthesis of 3-chloromethyl-2(5H)-furanones and 3-chloromethyl-5,6-dihydropyran-2-ones was developed. This reaction proceeded in a highly regioselective manner, i.e., the chlorine atom was introduced to the terminal position of the allene moiety while the lactone linkage was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of gamma-lactone 3p. The highly optically active 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available optically active 2,3-allenols. A mechanism for this reaction was proposed.
Cheng
Xin
X
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, People's Republic of China.
Jiang
Xuefeng
X
Yu
Yihua
Y
Ma
Shengming
S
D000438:Alcohols / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010165:Palladium / Q000737:chemistry*; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
D000438:Alcohols; D005663:Furans; D011753:Pyrones; D010165:Palladium; C008756:palladium chloride